A good article from the BBC's Frank Gardner on travelling with a wheelchair and some of the problems he has had getting on and off planes. Frank was paralysed from the waist down when he was shot while reporting in Saudi Arabia about 10 years ago.
I particularly like the shot of Frank wheeling himself across an airport with a walker slung around his neck - even with assistance I've found that sometimes, it's only for me, not anything I might have with me, even my crutches. I end up balancing a carry on between my feet and two crutches on my lap.
I travel much lighter than most people - very seldom do you see me with a full size carry on, usually I just pack a small backpack with what is needed for the flight and check everything else in. These days, that's an extra cost I somewhat begrudge. When we're heading to NZ, though, we usually have a reasonably large backpack each, since we both need at least one change of clothes (I still take an extra change for the small Scottish boy, in case of knocked over drinks on board). The boy is just about old enough to tow a decent size carry on case, but not when he is tired and grumpy. Which I think is pretty reasonable for a 7 year old after 19 hours on a plane.
Heathrow Terminal 5, where I was last week, had a really sturdy wheelchair which had room underneath for a full size carry on bag, plus hooks on the back for small bags. This was great as we hadn't checked anything in, so for once did have a full size cabin bag suitcase on wheels. I was betting on the small boy pulling it, but at a push I can manage on one crutch for short distances.
They were also more than happy to take me all the way onto my underground train (to Kings Cross, which now has lifts!) The only drawback was that it wasn't the sort you can wheel yourself, which meant a bit of juggling to get through some of the doors.
I *can* walk but I can't walk as far, nor stand as long, as is usually required in airports. So wheelchair assistance is a great help, which I use when I need it but not when I don't, but sometimes it could be done a bit better!